Trojan Boat Forum

I recently repowered my 1979 F32 from 305 mercs to 350 Merc Bluewater inboards. However once in the water we found that oil pressure gauges and water temp gauges were functioning incorrectly. Water temp was reading north of 220 and oil pressure was north of 80 psi. In actuality oil psi was marginally under 40 psi and water temp at 140 at ideal and climbed correctly when revving up engine.. We have checked all the wiring, checked the harness and all is good. We ran a temp wiring to bypass the harness and found the same readings. Both upper and lower gauges malfunction the same. We installed new water sensor with no improvement. We installed new oil pressure sensor which reads correctly in the salon but not bridge. Our next step is to try new gauges but that just seems wrong that the gauges on the bridge and salon all go south. Fuel and amp gauges al function properly in salon and bridge.
Has anyone experienced this issue after a Repower? Any assistance would be greatly appreciated.

Your boat cane with AC/Delco gauges, they will not work with any other sender than the old AC senders. So you could install your old senders or install new gauges. If you go the new gauge route the upper and lower must match. Also, the senders on the engine must be for dual gauges or they will read incorrectly. If someone has replaced the gauges and you no longer have the AC ones your engine could have the single gauge units


This will be helpful.

viewtopic.php?f=1&t=10222

Beacon has replacement gauges with the matching senders.

Thankyou very much